Suchergebnisse

pages, 7 figures, 1 table, supporting information.-- https://doi.org/10.1111/mec.15454.-- DNA sequences and associated metadata: European Nucleotide Database (ENA) under accession numbers ERP109198 and ERS2539749–ERS2539903. The environmental metadata, and the complete non-rarefied OTU and taxonomic tables used in this study are provided as Supporting Information (Tables S1, S2, S3 and S4).-- This is a contribution of Grup Consolidat de Recerca of the Catalan Government 2014SGR/1179 ; Deep ocean microbial communities rely on the organic carbon produced in the sunlit ocean, yet it remains unknown whether surface processes determine the assembly and function of bathypelagic prokaryotes to a larger extent than deep‐sea physico‐chemical conditions. Here, we explored whether variations in surface phytoplankton assemblages across Atlantic, Pacific and Indian ocean stations can explain structural changes in bathypelagic (ca. 4000 m) free‐living and particle‐attached prokaryotic communities (characterized through 16S rRNA gene sequencing), as well as in prokaryotic activity and dissolved organic matter (DOM) quality. We show that the spatial structuring of prokaryotic communities in the bathypelagic strongly followed variations in the abundances of surface dinoflagellates and ciliates, as well as gradients in surface primary productivity, but were less influenced by bathypelagic physico‐chemical conditions. Amino acid‐like DOM components in the bathypelagic reflected variations of those components in surface waters, and seemed to control bathypelagic prokaryotic activity. The imprint of surface conditions was more evident in bathypelagic than in shallower mesopelagic (200‐1000 m) communities, suggesting a direct connectivity through fast‐sinking particles that escapes mesopelagic transformations. Finally, we identified a pool of endemic deep‐sea prokaryotic taxa (including potential chemoautotrophic groups) that appear less connected to surface processes than those bathypelagic taxa with a widespread vertical distribution. Our results suggest that surface planktonic communities shape the spatial structure of the bathypelagic microbiome to a larger extent than the local physico‐chemical environment, likely through determining the nature of the sinking particles and the associated prokaryotes reaching bathypelagic waters ; This work was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through the Consolider-Ingenio program (Malaspina 2010 Expedition, ref. CSD2008-00077), with contributions from grant CTM2015-70340R, CTM2015-65720-R, CTM2015-69936-P, RTI2018-101025-B-I00, Modeling Nature Scientific Unit (UCE.PP2017.03), CTM2015-69392-C3-2-R (co-financed with FEDER funds) and King Abdullah University of Science and Technology (KAUST). [.] CRG was supported by a Juan de la Cierva fellowship and the GRAMMI project (IJCI-2015-23505 and RTI2018717 099740-J-I00, MICINN, Spain). MSE was supported by a Viera y Clavijo contract funded by the ACIISI and the ULPGC. MM was supported by CONICYT (FONDAP IDEAL15150003 and FONDECYT-POSTDOCTORADO 3190369).